Fire Debris, Fire Investigations and the Forensic Lab - Are We Missing Things? Or, Keeping Up with the Dogs Dr. John D. DeHaan

The need for “science” in fire scene investigation Started to change in the 1980 ’ s with new, science-based texts and a growing awareness of the need to get it right. Started to change in the 1980 ’ s with new, science-based texts and a growing awareness of the need to get it right. NFPA began the process to create the 921 Guide NFPA began the process to create the 921 Guide Court decisions (Daubert, Kumho, Joiner, Benfield, et al.) forced fire investigation to become more science-based. Court decisions (Daubert, Kumho, Joiner, Benfield, et al.) forced fire investigation to become more science-based. The “ Scientific Method ” is expected. The “ Scientific Method ” is expected. Experts Have to Support Their Conclusions and demonstrate reliability, acceptance, and use of published, peer-reviewed data. Experts Have to Support Their Conclusions and demonstrate reliability, acceptance, and use of published, peer-reviewed data.

Fire Investigations and the Forensic Lab If the investigator has no access to reliable answers based on good science, he or she will turn to less reliable sources such as those the oral history promulgated (often erroneously). If the investigator has no access to reliable answers based on good science, he or she will turn to less reliable sources such as those the oral history promulgated (often erroneously). The answers needed by today ’ s investigators go far beyond “ Was there an ignitable liquid in the debris? ” The answers needed by today ’ s investigators go far beyond “ Was there an ignitable liquid in the debris? ”

CRIMINALISTICS CRIMINALISTICS Debris containing suspected volatiles Debris containing suspected volatiles Liquids Liquids Charred or burned paper documents Charred or burned paper documents Clothing and shoes Clothing and shoes Tools and tool marks Tools and tool marks Dry blood stains DNA/saliva Glass fragments Paint chips Hairs and fibers Firearms Purpose: Aid in Reconstructing Events and Human Activities Link suspect and scene or victim and suspect

Debris containing suspected volatiles The most requested service The most requested service Well-studied and Documented by ASTM practices Well-studied and Documented by ASTM practices Isolation of volatiles from debris Isolation of volatiles from debris E1386: Solvent extraction E1386: Solvent extraction E1388: Headspace sampling E1388: Headspace sampling E1412: Passive headspace (C-strip) E1412: Passive headspace (C-strip) E1413: Dynamic headspace (charcoal tube) E1413: Dynamic headspace (charcoal tube) E2154: SPME E2154: SPME

Method Selection E1412: Most commonly used, easy, low cost, non-destructive, wide dynamic range E1412: Most commonly used, easy, low cost, non-destructive, wide dynamic range May miss light ends (Hydrocarbons under C7) if sampling time is too long May miss light ends (Hydrocarbons under C7) if sampling time is too long May miss heavy ends (hydrocarbons over May miss heavy ends (hydrocarbons over C18) if sampling time is too short or temperature is too low Uses solvent extraction Uses solvent extraction from carbon strip

Gas Chromatographic Analysis ASTM E1387: ASTM E1387: GC-FID: Characterization by peak pattern and retention times GC-FID: Characterization by peak pattern and retention times Original method: low cost, universal range Original method: low cost, universal range Well-suited to: gasoline, paint thinner, kerosene, diesel, light distillates, and “ miscellaneous ” class: blends and non- distillate products Well-suited to: gasoline, paint thinner, kerosene, diesel, light distillates, and “ miscellaneous ” class: blends and non- distillate products Proliferation of new “ custom ” petroleum products and non-petroleum products Proliferation of new “ custom ” petroleum products and non-petroleum products “ De-certified ” by ASTM E-30 in 2010 “ De-certified ” by ASTM E-30 in 2010

Gas Chromatographic Analysis GC/MS became necessary to make many identifications GC/MS became necessary to make many identifications First published as ASTM E 1618 in 1994 First published as ASTM E 1618 in 1994 Capable of “ separating ” aliphatics, aromatics, cycloalkanes, and unsaturated compounds Capable of “ separating ” aliphatics, aromatics, cycloalkanes, and unsaturated compounds Retention times, peak profiles, target compounds, aromatic:aliphatic ratios are now criteria Retention times, peak profiles, target compounds, aromatic:aliphatic ratios are now criteria Now multiple classifications: seven major classes, divided by boiling point range, plus automotive gasoline, for a total of 21. Now multiple classifications: seven major classes, divided by boiling point range, plus automotive gasoline, for a total of 21. E1387 dropped as a recommended method in E1387 dropped as a recommended method in Heavy products no longer separated into kerosene class v. fuel oil class Heavy products no longer separated into kerosene class v. fuel oil class

GC/MS: The Only Answer? With solvent injection methods, most GC/MS operators sacrifice all peaks that elute before the solvent (diethyl ether, dimethyl ether, or carbon disulfide) With solvent injection methods, most GC/MS operators sacrifice all peaks that elute before the solvent (diethyl ether, dimethyl ether, or carbon disulfide) This means that many This means that many light products including: ethers, ketones, alcohols and C6 range hydrocarbons are not recorded. These may be critical to These may be critical to the evidence.

Jumping straight to selected ions The overall pattern of peaks is very important in the characterization process The overall pattern of peaks is very important in the characterization process Start with the TIC! Start with the TIC! Skipping straight to looking for aromatic v. aliphatic peaks or even target compounds can result in misleading conclusions Skipping straight to looking for aromatic v. aliphatic peaks or even target compounds can result in misleading conclusions

Blind Spot Because the heavy distillates are no longer split, it is OK to report “ heavy petroleum distillate ” and list kerosene and diesel fuel as candidates Because the heavy distillates are no longer split, it is OK to report “ heavy petroleum distillate ” and list kerosene and diesel fuel as candidates This has led to mischaracterization of kerosene as diesel fuel and This has led to mischaracterization of kerosene as diesel fuel and vice versa (not by the analyst but in court by the investigator or the prosecutor). The analyst has to know what issues are important and modify the technique used. The analyst has to know what issues are important and modify the technique used.

Lab Analysis Not just for Volatile Accelerants! Not just for Volatile Accelerants! Identification of Fuels Identification of Fuels Laboratory Identification Laboratory Identification By chemical, physical, or microscopic methods By chemical, physical, or microscopic methods Field Tests Field Tests Fire Tests Fire Tests

Fire Investigations and the Forensic Lab Furnishings and Clothing: Furnishings and Clothing: Are they natural fibers – cotton, linen, wool? Are they natural fibers – cotton, linen, wool? Are they synthetic – polyester, polypropylene, nylon, acrylic, or ??? Are they synthetic – polyester, polypropylene, nylon, acrylic, or ??? Are they thermoplastic, or thermosetting, or elastomers? Are they thermoplastic, or thermosetting, or elastomers? Melting points? Ignition temperatures? Melting points? Ignition temperatures? What volatile products do they generate? What volatile products do they generate? Foam – polyurethane, polyether, or latex? Foam – polyurethane, polyether, or latex? Are there fire retardants present? Are there fire retardants present?

What Can the Lab Tell? General type of fuel may help identify or exclude competent ignition sources. General type of fuel may help identify or exclude competent ignition sources. Is the Fuel First Ignited Cellulosic? Is the Fuel First Ignited Cellulosic? Cellulosic: Derived from Plants Cellulosic: Derived from Plants Wood Wood Paper Paper Cotton Cotton Linen Linen Cardboard Cardboard Susceptible to smoldering Susceptible to smoldering Crumbly grey/black ash on burning Crumbly grey/black ash on burning White smoke White smoke Cellulosic fuels are susceptible to hot surface/glowing ember ignition

What Can the Lab Tell? Is the Fuel First Ignited Synthetic? Is the Fuel First Ignited Synthetic? Most Synthetics are petroleum derivatives Most Synthetics are petroleum derivatives Nylon Nylon Polyethylene Polyethylene Polystyrene Polystyrene Polyester Polyester Rarely ignitable by smoldering/hot surface source Rarely ignitable by smoldering/hot surface source Easily ignited by open flame Easily ignited by open flame Tend to melt and shrink away from heat Tend to melt and shrink away from heat Most do not sustain smoldering combustion Most do not sustain smoldering combustion

What Can the Lab Tell? Synthetics: Synthetics: May be thermoplastic – melts without degrading May be thermoplastic – melts without degrading May be thermosetting (resin) – degrades, chars, may smolder May be thermosetting (resin) – degrades, chars, may smolder Other fuel types: Other fuel types: Elastomers (rubbers): Synthetic or natural Elastomers (rubbers): Synthetic or natural Leather – Wool – Silk: Proteinaceous (from animals) Leather – Wool – Silk: Proteinaceous (from animals)

Field Testing NFPA 705: Field Flame Tests for Textiles and Films – Recommended Practice 1997 Even a simple IST (ignition susceptibility test) has a pedigree: NFPA 705: Field Flame Tests for Textiles and Films – Recommended Practice 1997 Small flame (lighter or match) held to bottom edge or corner of small sample held vertically in air. Small flame (lighter or match) held to bottom edge or corner of small sample held vertically in air. Observe flame color and behavior Observe flame color and behavior Observe smoke color and production odor Observe smoke color and production odor Blow out and observe smolder (if any) Blow out and observe smolder (if any) Test ash texture Test ash texture

Fire Investigations and the Forensic Lab WHY? WHY? Because the investigator will be expected to justify his or her conclusions about ignition, flame spread, and size of the fire on that data. Because the investigator will be expected to justify his or her conclusions about ignition, flame spread, and size of the fire on that data. Cigarettes will not ignite most synthetics but will ignite most cellulosic materials. Cigarettes will not ignite most synthetics but will ignite most cellulosic materials. Open flames will quickly ignite most synthetics or blends, but then what will the fabric do? Open flames will quickly ignite most synthetics or blends, but then what will the fabric do? Self-heating processes do not result in ignition of thermoplastic substrates. Self-heating processes do not result in ignition of thermoplastic substrates.

CRIMINALISTICS CRIMINALISTICS Debris containing suspected volatiles Debris containing suspected volatiles Liquids Liquids Charred or burned paper documents Charred or burned paper documents Clothing and shoes Clothing and shoes Tools and tool marks Tools and tool marks Blood stain patterns DNA/saliva Glass fragments Paint chips Hairs and fibers Firearms Purpose: Not Just for Identifying Things! Aid in Reconstructing Events and Human Activities Link suspect and scene or victim and suspect

Criminalistics (Non-Fire) Evidence Investigators must be aware of proper collection and preservation methods for each type of evidence Investigators must be aware of proper collection and preservation methods for each type of evidence The lab needs to get involved in training! The lab needs to get involved in training! Chain of custody traces an item of evidence from its discovery to court. Chain of custody traces an item of evidence from its discovery to court. Spoliation is the destruction or alteration of evidence. Spoliation is the destruction or alteration of evidence. ASTM E 860 establishes practices for examining and testing of evidence which may be involved in criminal or civil litigation. ASTM E 860 establishes practices for examining and testing of evidence which may be involved in criminal or civil litigation.

Other Relevant ASTM Guidelines ASTM E620: Practice for Reporting Opinions of Technical Experts ASTM E620: Practice for Reporting Opinions of Technical Experts ASTM E678: Practice for Evaluation of Technical Data ASTM E678: Practice for Evaluation of Technical Data ASTM E1188: Standard Practice for Collection and Preservation of Information and Physical Items by a Technical Investigator ASTM E1188: Standard Practice for Collection and Preservation of Information and Physical Items by a Technical Investigator ASTM E1459: Standard Guide for Physical Evidence Labeling and Related Documentation ASTM E1459: Standard Guide for Physical Evidence Labeling and Related Documentation ASTM E1492: Receiving, Documenting, Storing and Retrieving Forensic Evidence ASTM E1492: Receiving, Documenting, Storing and Retrieving Forensic Evidence

Fire Investigations and the Forensic Lab Flash Point? Flash Point? Melting Point (or Softening Point)? Melting Point (or Softening Point)? Does this material burn by smoldering, flaming, or both? Does this material burn by smoldering, flaming, or both? Ignition Conditions – vapor pressure, autoignition temperatures, conditions? Ignition Conditions – vapor pressure, autoignition temperatures, conditions? What would be the effect of enhanced oxygen or reduced oxygen concentrations? What would be the effect of enhanced oxygen or reduced oxygen concentrations?

Fire Investigations and the Forensic Lab What Is That Mess? What Is That Mess? What Was It and How Did It Get That Way What Was It and How Did It Get That Way Physical exam Physical exam UV/ALS UV/ALS X-rays X-rays Elemental analysis Elemental analysis SEM SEM Broken by mechanical Broken by mechanical force, shock, or heat? force, shock, or heat? Exemplars? Exemplars?

Fire Investigations and the Forensic Lab Clothing items: Clothing items: Impact or transfer patterns - actions Impact or transfer patterns - actions Thermal – scorching, melting, charring, color changes – position and posture of wearer Thermal – scorching, melting, charring, color changes – position and posture of wearer Bloodstains – presence, patterns, toxicology Bloodstains – presence, patterns, toxicology Thermal properties – conductive or transparent to infrared – related to burns or protect areas on body Thermal properties – conductive or transparent to infrared – related to burns or protect areas on body

Fire Investigations and the Forensic Lab Shoe, tire, or tool impressions Latent fingerprints Body fluids - DNA

Fire Investigations and the Forensic Lab What can the broken glass and bloodstains on this door tell the criminalist? DNA alone doesn ’ t tell the whole story!

Fire Investigations and the Forensic Lab Recognition of trace evidence – glass, fibers, paint, soil - and toolmark evidence and their forensic significance. Recognition of trace evidence – glass, fibers, paint, soil - and toolmark evidence and their forensic significance. Who else can or should do it? Who else can or should do it?

Fire Investigations and the Forensic Lab Glass: Thermal or mechanical break? Type? Match to Source? Reconstruction? DNA on the mouth of the bottle!

Fire Investigations and the Forensic Lab New Innovations Need to be Properly Tested. New Innovations Need to be Properly Tested. Sniffers Sniffers Absorbent materials Absorbent materials Containers Containers UV and ALS detection of “ accelerants ” UV and ALS detection of “ accelerants ” CANINES CANINES GC/MS/MS GC/MS/MS

Keeping Up with the Dogs In the late 1980 ’ s canine “ accelerant detection teams ” were introduced. In the late 1980 ’ s canine “ accelerant detection teams ” were introduced. Their sensitivity to odors was quickly proven superior to lab methods. Their sensitivity to odors was quickly proven superior to lab methods. Conflicts grew when handlers insisted that a canine alert was proof of the presence of an ignitable liquid even when the lab results were negative. Conflicts grew when handlers insisted that a canine alert was proof of the presence of an ignitable liquid even when the lab results were negative.

Keeping Up with the Dogs Analysts were forced to improve the sensitivity of lab methods to the ppb levels of the canines. Analysts were forced to improve the sensitivity of lab methods to the ppb levels of the canines. Then we discovered that there were many products (carpet, clothing, shoes, copy paper, etc.) that contained traces of solvents from their manufacture. Then we discovered that there were many products (carpet, clothing, shoes, copy paper, etc.) that contained traces of solvents from their manufacture. The issue was not of sensitivity but of the selectivity needed to discriminate between innocuous contaminants and significant residues of real accelerants. The issue was not of sensitivity but of the selectivity needed to discriminate between innocuous contaminants and significant residues of real accelerants. GC/MS is the only defensible technique. GC/MS is the only defensible technique.

Fire Investigations and the Forensic Lab Now that we can be as sensitive as the dogs, the question became: Is There Such a Thing as “ Too Sensitive ” ? Now that we can be as sensitive as the dogs, the question became: Is There Such a Thing as “ Too Sensitive ” ? What Do We Know About the Substrate and Its Possible Background Contributions? What Do We Know About the Substrate and Its Possible Background Contributions? What control or comparison samples exist? What control or comparison samples exist? Can “ Old ” residues be significant? Can “ Old ” residues be significant?

Fire Investigations and the Forensic Lab This fire in Pennsylvania killed two elderly people. An adult son escaped and was charged with their murder based on burn patterns in the room of origin and the presence of traces of highly evaporated gasoline in the wood floor (but not in the carpet or pad).

Fire Investigations and the Forensic Lab New petroleum products and new uses for not-so-new products have added to the difficulty of interpreting GC results New petroleum products and new uses for not-so-new products have added to the difficulty of interpreting GC results GC/MS almost mandatory today GC/MS almost mandatory today Aware of contributions of fuels involved Aware of contributions of fuels involved Comparison samples essential Comparison samples essential Substrates AND products Substrates AND products Pyrolysis products in both oxygenated and oxygen deprived conditions Pyrolysis products in both oxygenated and oxygen deprived conditions

Fire Investigations and the Forensic Lab We cannot come to correct conclusions without context. We cannot come to correct conclusions without context. We cannot deliver valuable analyses by “ rote ” methods (unlike drugs, blood alcohol or even DNA). We cannot deliver valuable analyses by “ rote ” methods (unlike drugs, blood alcohol or even DNA). We owe it to our clients to offer the best array of services We owe it to our clients to offer the best array of services Many of the reliable and useful techniques are so rarely used that no “ ASTM ” technique exists BUT Many of the reliable and useful techniques are so rarely used that no “ ASTM ” technique exists BUT That does not mean we should not offer them as long as they are based on good science! That does not mean we should not offer them as long as they are based on good science!

Thank you! John D. DeHaan, Ph.D., F-ABC, CFI, FFSSoc Fire-Ex Forensics, Inc Sonoma Blvd # Vallejo CA (Fax) WE must prepare criminalists with the broad scientific knowledge AND the reasoning capacity to evaluate real evidentiary problems and properly select, use, and defend the procedures used to solve those problems.